


Rules are Rules

by Cookiemonster2000



Category: Invader Zim
Genre: Alternate Universe, BUT NO UNDERWEAR GETS TAKEN OFF., Crushes, F/M, Gaz just wants to see how irken bodies work, High School, Mentions of Dissection, One-Sided Attraction, Roleswap, Strip Poker, and if that means she gotta trick zim into letting her inspect him she's willing to do it, or is it...., so basically Gaz is Dib and Zim is Tak (kind of), this is the most self indulgent thing ive ever written
Language: English
Status: Completed
Published: 2020-05-02
Updated: 2020-05-02
Packaged: 2021-03-02 04:14:51
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,563
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23959051
Author URL: https://archiveofourown.org/users/Cookiemonster2000/pseuds/Cookiemonster2000
Summary: Zim, in a state of denial about his feelings, nonetheless knows the dangers of being alone with Gaz, especially when her greatest wish is to dissect--or in the very least, analyze his alien body. But Zim's competitive nature can't resist when Gaz makes him a challenge he can't refuse--the opportunity to put her in his shoes for once.- - -Strip poker fic with heavy pining and obliviousness.
Relationships: Gaz/Zim (Invader Zim)
Comments: 2
Kudos: 32





	Rules are Rules

**Author's Note:**

> this might be the most self-indulgent thing i've written in a while. in case you skimmed the tags, this story is set in the roleswap universe, in which Gaz swaps places with Dib and Zim swaps places with Tak. Gaz is obsessed with the paranormal and Dib is uninterested in anything but video games; Tak is a total screw-up who desperately wants the respect of her Tallest and Zim is the much more manipulative alien with a darker plan in mind.  
> Unfortunately Zim didn't count on getting a massive crush on the girl who won't stop talking his ear off. so he's sticking around after Tak destroyed his ship until he can repair it, supposedly. that's all you need to know.
> 
> GIANT MASSIVE THANKS TO CEL for beta reading and editing this work, it looks sooo much better now. Her account name is potatoes_tomatoes and she has her own fics and art!! check her out!!

“Absolutely not.”

There were plenty of things Zim would do for Gaz, the only human smart enough to both see through his disguise and to help fix his broken ship. She had an affinity for the supernatural, the strange, and that just happened to include him.

Unfortunately, that meant she had a fascination with him from the get-go. And that had, as much as he liked to pretend it did, nothing to do with him and everything to do with his species. And besides that, allowing any foreign alien not under the total control of the Irken empire to study their biology and possibly find out weaknesses and, Tallest forbid, develop some kind of chemical weapon against them. . . well, needless to say it was entirely against _all_ the rules he had been programmed with.

Which is why when she came to him with her offer, his response was flat-out rejection.

She slumped over and pouted, of course. “What?? Why not?”

“Because.” He felt his face heating up and willed it away at once, letting his voice take on a harsher tone. “You’re a human, an inferior species.  _ As if _ I would ever take off my disguise in front of you, let alone allow you to study my anatomy.”

“But your anatomy is fascinating!” she chirped, and he scooted back a tad and reminded himself that she didn’t mean that at  _ all _ the way it came out. “And you’re the coolest alien at our school!”

“There’s only two of us, and you pick a fight with Tak every day.”

“That’s because she’s trying to take over Earth.” Gaz shook her head. “ _ You’re  _ just passing through.”

“Well.”

_ Liar _ .

“I’m still not going to do it." He shook off the wave of guilt that swept over him momentarily. "My pride is at stake here, Gaz.”

“ _ Your _ pride?” She sounded incredulous. “It took a lot of humility to even  _ come _ to you with this! I thought you promised to  _ help _ me!”

“I promised to help you stop Tak from taking over the planet until  _ you  _ help  _ me  _ get my ship up and running again. This? This isn’t helping, this is a personal thing.” 

While he was talking, she had scooted closer to him, peering into his eyes. “It’s not personal! . . . It’s  _ science _ .”

Zim, uncomfortable with their proximity, edged backwards again, his back hitting the wall behind them in the lab. “You’re lucky I venture into your little hellhole at all.”

“C’mon, none of this stuff’ll hurt you unless I tell it to.” Gaz grinned and elbowed a vicious-looking stuffed animal. Zim watched its eyes sputter with a low red glow before going out.

Seeing his face was serious, Gaz’s smile dropped into a pout. “What? There’s  _ nothing  _ I can say to convince you?”

Zim thought of Gaz putting a stethoscope against his bare chest and her fingertips touching his skin and her sweet-smelling hair hanging over his shoulder as she cooed breathily over his strange pulse.

His claws dug into the floor. “Nothing. Never. Not going to happen.”

Gaz squinted at him a few seconds more. Then she sat up abruptly, tapping her finger to her chin.

“Well, I guess I’ve got to give up,” she shrugged. “After all, once the incredible Zim makes his decision, nothing can possibly sway him.”

He felt his chest fill with warmth upon hearing her flattering words. “Well. I am Irk’s mightiest invader, after all.”

“Of course you are!” she said without an ounce of sarcasm. He felt himself inflate like a balloon.

It sputtered only slightly when she continued--

“Which is why I wouldn’t have a chance in beating you at the  _ game _ .”

His antennae perked up under his disguise.

“What  _ game _ ?”

“Oh, nothing.” Gaz stretched and leaned away from him. “I was going to suggest a little friendly contest between us, is all. But I have no chance of getting you to even  _ play  _ with me. Shame, really, considering the prize. . .”

“Prize? What prize? Tell me. You will tell me at once.”

“The prize is a surprise. But the game is a prize in itself. . . it gives you the opportunity to prove your, ahem,  _ superiority _ to your opponent.”

Zim blinked owlishly. “I am superior.”

“So why are you scared to prove it?”

“Are you trying to bait me?”

“Do you think I think of you as that easy to bait?”

He growled and rubbed his temple. “What is the name of this game.”

She peered up at him behind her glasses, a peculiar look in her eyes. He caught the barest hint of a smirk before her innocent little frown returned.

“Ever heard of  _ strip poker _ ?”

  
  
  


Which is how he ended up in the school’s resident crazy girl’s basement, squinting at a pair of cards in his hand. His eyes shifted up at hers beadily, trying to catch a change in emotion, but she was a blank slate. He groaned.

The rules were simple, supposedly. Fifteen chips were the equivalent to one clothing article lost. Zim had been betting low for the first three rounds, but Gaz still beat him every time and now she had twelve on top of her starting thirty.

"You gonna cash in?" he asked, trying to contain the nervousness in his voice.

"Why would I do that so quickly?" She smiled sweetly. "I like watching you squirm."

Zim huffed and settled down, hiding his cards nervously.

He still had a rudimentary understanding of what was good and what was bad. Face cards seemed to be the best. A player wanted cards similar to each other in value as well, and matching the cards in play. This hand Zim had, again, nothing good, but folding is what had caused him to lose chips in the first place, so he couldn't afford to give up so easily again.

Gaz straightened up and Zim's attention zeroed in on her, but she only opened her mouth to say “I raise you five.”

He raised an eyebrow as she slid five chips into the pot.

" _ Really _ ?"

"Are you folding?" She didn't even look at his face, her tone light.

Zim checked and cursed silently as she placed the final card down. Still nothing helpful. The universe was conspiring to get him undressed in front of his-- the wannabe butcher.

“You ready to give up your disguise?” she teased.

“No. I will  _ not _ lose.”

“Whatever you say, Invader,” Gaz said as she slapped her cards down on the table. Three of a kind.

Zim glared at it, as if his animosity would change the results.

“Pay up or show your winning hand.”

He put his cards down. Two pair.

"Sweet." Gaz slid the pot towards herself, then counted out fifteen chips. 

He considered getting up and leaving. Gaz leaned back into the wall and raised her eyebrows, crossing her arms.

"Well?"

Zim breathed a sigh of the long-suffering and clicked his holographic disguise off. As the effect disappeared, leaving only his Irken form in its place, he could see the light in Gaz’s eyes brighten up. Her eyes went from his antennae to his tunic to his legs and back up until he was sure she’d already drunk in every inch of his body without needing to take off a single piece of clothing. 

It was terrifying, and also gorgeous. 

… But mostly terrifying, considering her scrubbed clean metal operation table with wrist restraints was less than three yards away.

“Enjoying the view?” he said, because he couldn’t help himself.

“Oh, absolutely.” She finally met his eyes again, and he wasn’t sure if he hated or loved the look in hers. “But believe me, I’ll enjoy it even more when every  _ stitch _ of that uniform is off.”

Which tipped it  _ far _ too far in one direction.

“In your dreams,” he managed to spit, quickly dealing the next round. While he simmered in embarrassment, he could hear her giggling, which kind of made the flip-flopping of his insides even worse.

The next hand Zim was surprised. He had something for once, something helpful. He attempted to conceal his smile and raised the bet four.

Gaz grinned at that. “Finally figured out how to bluff, huh?”

He chose not to answer, instead gesturing to the pot.

“Fine, I’ll see you.” She pushed a couple of chips in, then stopped. “And raise two more.”

That was fine with Zim, who allowed her bet to stand. The next card placed down, he almost couldn’t contain his grin--if his victory wasn’t assured already, an additional corresponding face card was sure to do the trick.

He raised five.

“Feeling lucky this round, aren’t you.” Her eyes were sharp.

“Something like that.” He didn’t back down.

Gaz glanced between her cards and the pot. Finally she shrugged and tossed her cards down.

“Whatever, I fold.”

“Does that mean I get the chips?” Zim’s antennae perked up.

“Yeah, pot’s yours.”

He greedily slid the pile towards himself. Gaz shook her head at him. “You gotta cool it on the betting when you’ve got a good hand. You’re not a very good actor, you know.”

“Why’d you raise it again, then?”

“Testing a hypothesis.” She winked.

He counted out fifteen chips. At her bewildered expression, he bit back a smug grin.

“Already?”

“Yes.”

Gaz folded her legs beneath her and chewed her lip. She stared at the pile.

“So?”

“So, what?” She was unimpressed.

“So, what are you taking off?” he asked a bit too quickly, staring at the ceiling.

Gaz considered. She reached up and pulled her bright green headband out of her purple hair, tossing it over her shoulder. “There.”

Zim huffed. “That’s cheap.”

“It’s clothes. It counts” Her smirk was infuriating. She ran a hand through her now-disheveled hair. “You should probably wear more.”

“You should wear  _ less _ !” he shot back.

“Oh, you  _ wish _ .”

“ _ What _ ?”

“What.”

The air suddenly felt different. Zim quickly looked away from her burning eyes and slid a few chips into the pot. “Uh. I’ll start.”

“Nah, we’re both running low now. Stock the pot with chips that aren’t in play so we can get more in circulation.”

The next round, she was careful not to show any emotion whatsoever. But by this point, the stakes were up. Zim wasn't about to lose another round or he'd start losing boots, and he only had two before his belt and single-piece tunic would have to come off. Which was not acceptable.

He studied his hand--not great, like last time, but still good. He concealed a smile and glanced at her. 

She was looking at him. Bingo.

He faked a yawn and raised the bet. Gaz checked. The next card wasn’t anything helpful, but Zim raised the bet again anyway.

She checked again. She seemed to not be taking the game seriously, which was annoying. Didn’t she consider Zim a worthy opponent? That was why she had accosted him in such a way to begin with, wasn’t it? 

He already knew she was only interested in his body, and not even in  _ that  _ way. He’d be lucky if he escaped her basement with all his toe claws as it was. Why did he come down here to hang out with her anyway?

Zim decided he was going to win. He was always going to win, of course, but now he was even more certain. As Gaz ran a hand through her hair thoughtfully and squinted at the cards in her hand, he allowed himself to take the view of her in more fully--legs folded underneath her body, shoulders hunched over ever-so-slightly, lips pouting. His eyes drifted down just a tad to where her blue shirt concealed her chest. Nothing about her evolutionary advantages was of the least interest to him initially--humans were confusing and unappealing. But the more he got to know her personally, the less her alien physique disgusted him until he wasn’t sure if there was any disgust left at all. Now found himself wanting to win for slightly different reasons than before, reasons he shouldn’t even be gracing with more than a fleeting moment’s presence in his mind..

What would Gaz look like without her clothes on? How would she act? She’d want him to think she’s shameless, but she’d be more and more embarrassed the more that came off. She certainly would be forced to pay closer attention to him, right? Maybe losing this game would be what it took to make her look at him in a different light--

She slapped her cards down, startling him out of his thoughts. He shook his head rapidly, dispelling the guiltiness of his train of thought, as she grinned at him.

He lost a boot.

  
  
  


The night had zipped by. With no windows in the basement, it was hard to tell that time was passing. Though he was down to his last garments-- his one-piece tunic and the minimal concealing wear underneath--Zim had managed to win enough rounds that Gaz’s trench coat, shoes, and tights were off. 

(He had turned around as she pulled them out from under her skirt, but then she’d laughed and he’d turned back around to spite her. “It’s strip poker and you’re trying to keep from seeing any stripping?”)

“Let’s see what you’ve got.”

Zim blinked at her cards and put his own down next to hers.

“I think. . . No, I win.”

“What?” She looked down in disbelief.

“I win,” he said evenly, trying to conceal his glee. “I  _ beat  _ you.”

“You--ughh.” Gaz offered him a begrudging smile.

His eyes didn’t leave hers. She sighed.

“Fine, fair’s fair.”

He watched as she reached down and pulled her shirt up over her head, tossing her hair slightly aside as she folded it and neatly set it down beside her. She was wearing a gray sports bra, with straps crossing over her chest. Not incredibly revealing, as those kinds of things went, but much,  _ much _ more than he’d ever seen.

She crossed her arms over her belly (she was so pale, why did she seem to be flushing, it wasn’t very cold down here) and looked up at the ceiling.

“Your skirt’s next,” he blurted without thinking.

Her eyes swiveled to his. Now her face was completely colored,  _ good _ . Maybe she was regretting suggesting such a dumb game in the first place. She looked as embarrassed as she always made him feel.

“Funny. I was thinking  _ your _ skirt was gonna be next.” she bit back.

“Skirt? This isn’t a skirt.” He was offended. “This is a tunic.”

“Right. In any case, it’s coming off your body.” She did that thing again, when her eyes roved down his body, and he shuddered.

"What?"

Zim shook his head rapidly, trying to dispel the cloudiness that kept threatening his intelligent, rational brain.  _ She wanted to cut him open. _ "Nothing. Nothing is coming off."

Gaz had begun dealing again. "Mhm," she purred. "Sure."

He grimaced and picked up his hand as she flipped over the cards.

To his surprise, he had a pretty good shot this time. An ace and a ten in his hand and an ace in the center--that was good. All he had to do was pretend he had nothing.

Zim settled into a neutral-displeased face. He saw Gaz catch his eye and smile, very small.

"Feeling antsy, alien boy? Check.”

“Not at all, freaky human girl. Check.”

“You’re gonna be feeling antsy in a minute.” Another card placed in the center. Nothing for him but it didn’t matter, he had to retain his composure. “Check.”

“Oh, am I?” Playing it safe wasn’t working. He needed chips. “I raise you three.”

Gaz didn’t even blink. Why was she so  _ good  _ at this?? “Yes, you certainly are. I see you. . . and raise two.”

“I’m sure you think so. Check.”

“Check. Glad we’re in agreement.” Gaz turned over the last card and a wide grin split across her face. Zim mirrored her expression--it was another ace, perfect.

“Want to raise? I’m checking again. No sense in taking the rest of your chips, there’d be no fun in completely breaking your spirit.”

“I guess I can take pity on you this time,” Zim said, completely ignoring her. “Check.”

“Great, because I have a straight.” She flipped over her two cards-- a two and a four. In the center sat two aces, a three, and a five.

“I have three aces!” Zim flipped his cards over triumphantly. “Hand over the pot.”

“Nope, straight beats three of a kind, even if they are aces. Pot’s mine.”

“What??” he demanded. “That isn’t true. These rules are stupid! Aces are clearly the most powerful cards!!”

“Rules are rules. And these ones say. . .” Gaz clicked her tongue and counted out thirty chips. “. . . take off your clothes.”

Zim clamped his arms around his chest and glared. “Absolutely not!” 

“Rules are rules, take it off!” She looked maniacal.

“No! I won and I want to see your legs!” he didn't care what came out of his mouth, he was  _ pissed _ .

“Well, you can’t! I want to study your guts, just--”

He gritted his teeth. She really had no idea. “I want to _study_ _you_ a lot more than you want to study me!”

Gaz ignored him and leaned over, taking hold of the bottom of his tunic, right below his hips. He reeled at her audacity.

“How DARE you lay a hand on ZIM!!” He grabbed her wrists, forcing them up and against the wall. “I won and you  _ know _ it!!”

"Shut the hell up, you sore loser, and take your clothes off!" She struggled to free her hands, suddenly bringing up her knee and jamming it between his legs in a desperate attempt to ward him off. "Come  _ oooon _ !"

" _ Ow _ !!" Without thinking, his Pak legs shot out, seized her ankles, and pressed them against the wall. She whined and slumped down a bit. Zim’s eyes snapped to her heaving chest, suddenly aware of their intimate position. He quickly looked away, not wanting to stare her directly in the face with their bodies so close.

"Fine, let me go." She blew a stray strand of hair out of her face and puffed her cheeks out. “Cheater. I won’t do anything.”

"You're a little liar." Nevertheless, his grip weakened considerably. 

She peered up at him under her eyelashes. "Don't you  _ twust  _ me?"

"Ew."

Gaz laughed. He softened despite himself and his grip loosened even more--her voice really was beautif--

She abruptly head-butted him.

Zim stumbled backwards for only a second but that was enough. She had her arms around his waist and was pulling upwards violently. The tunic caught around his chin and he flailed, trying to ward her off, but suddenly there was a weight on his chest and he fell on his back. The tunic came off, his antennae curled around his head instinctively for protection. 

He opened his eyes to see her sitting on him, chest heaving from the effort, hair a mess, eyes sharp and victorious and looking right into his.

He inhaled as a million thoughts flew through his head, each one less rational than the last, until all that was left was  _ revenge revenge revenge revenge _ and his eyes flicked downwards to how close her hips were to his claws and before he even realized what he was doing, he had taken a hold of her waistline and pulled as he sat up, causing her to tumble backwards off him onto the floor and  _ oh Tallest he was holding her skirt. The one that was just on her body. It was warm and it was just  _ on _ her and she was  _ **really** _ gonna kill him now. _

_ Her  _ back hit the wall and the glee in her face was gone, replaced with something akin to fear. He didn’t like that. 

He didn’t want her to be scared of him.

Zim balled up the skirt and threw it at her, turning around completely to face the wall. “Sorry. I’m sorry. I didn’t mean to.” he mumbled. “It was an accident.”

He didn’t turn back around until she cleared her throat. She was wearing the skirt again, but it was lopsided. Her hair was disheveled and gorgeous and her cheeks were the rosiest he’d ever seen them.

“Sorry,” he said again.

She twiddled her thumbs bashfully, not meeting his eyes. The downwards tilt of her head concealed her expression, but her voice was quiet and whispery. “It’s ok, I was being. . . really aggressive. But you can make it up to me.”

“How?” he breathed.

A moment after, he completely regretted asking, because her face popped up in a maniacal grin and she whipped a handheld scanner out of nowhere. He took a step backwards, but hit the wall again.

“Now that your pesky clothes are gone, I can scan your insides without obstruction!” she chirped, skipping over and tugging him down to a sitting position on the floor again. “Now, lie down!”

  
  
  
  


Gaz flitted over his bare chest, hands and breath mixed in a heat of excitement as she scrutinized his organs and bone structure. He figured it was a fitting punishment for an alien freak like himself, especially given the way he'd been thinking for the past hour or so.

Zim consoled himself as he faintly responded in pain, maybe a tiny hint of excitement too, that at least she didn’t feel the need to use the hand restraints.

**Author's Note:**

> how obvious is it that i've only ever played low stakes texas holdem? . . . yeah ok fair


End file.
